Major and minor depression in the postpartum period occurs in 10-15 percent of all new mothers, representing a significant public health problem. One of the major mechanisms by which PPD may influence infant outcomes is through its impact on the quality of the mother's affective and behavioral interactions during infancy, a critical time when physiological and emotional regulation and the capacity for human attachments are developing. Risk for disturbances in the mother-infant relationship as well as developmental delays and psychopathology in their infants represent significant areas of morbidity associated with postpartum depression and have not been addressed adequately by current intervention approaches. Therefore, the investigation of the efficacy of mother-infant relational treatment approaches for major depression during the postpartum period is warranted. The proposed study, representing a revision of the first R01 application by the principal investigator has four major aims: (1) To compare the efficacy of a manualized, relationally focused group treatment approach (M-ITG) for women with major depression in the postpartum period and their infants with a standard individual treatment (IPT) to ameliorate depressive symptoms and reduce recurrent episodes; (2) To compare the efficacy of M-ITG and IPT in improving the quality of mother-infant interactions; (3) To determine whether improvements in the mother-infant interaction mediate the impact of maternal depression on infant emotional, behavioral, and attention regulation; and (4) To examine the unique effects of depression severity and chronicity, comorbid anxiety and personality pathology on mother-infant interaction quality, and infant outcomes. Two hundred and eight women meeting criteria for major depression will be randomly assigned to one of two treatments for depression (1) M-ITG for mothers and their infants or (2) IPT. Assessments of mother, infant and mother-infant dyadic functioning, as well as parenting stress and marital conflict will be conducted at pre and post-treatment and at two follow-up points(l2 months post-treatment and when the infant is 24 months of age). Measures include diagnostic interviews, self and other report instruments and observational coding methods. The long-range objectives addressed by this research are to identify an effective intervention for postpartum depression that also reduces recurrences of depressive episodes in mothers, prevents subsequent psychopathology in their young children, and identifies key relational mechanisms that may inform the development of specifically targeted preventive interventions for high-risk dyads.